Can guns that shoot supersonic bullets be silenced?

[cjwils]

My understanding is that a supersonic bullet makes its own sonic boom, so no matter what you do to the gun, you will hear a loud noise. Am I correct, or can a gun with supersonic bullets be silenced to a significant degree? Just today, I saw a news article about poachers in Africa using "high-powered" rifles with "silencers." Is that feasible?

 

[RETG]

Never seen a suppressor that completely silenced a round. A suppressor cuts down the sound from the gas pressure created in the chamber and barrel another sound is from the bullet breaking the sound barrier. However, many common rounds (such as 9mm) are supersonic unless they have a heavy bullet. So the gas pressure is suppressed, but the crack of the speed of sound being broken is not.

Now to define "loud noise." My feelings are the crack is not a loud noise as compared to the gas expelling from the barrel.

I will say I have not shot a suppressed handgun in probably over 20 years, and then it was almost always a 9mm and modern suppressors are a lot better than the ones we had many moons ago.

Was that the article where the poachers became dinner for the lions?

 

[boom boom]

My understanding is that a supersonic bullet makes its own sonic boom, so no matter what you do to the gun, you will hear a loud noise. Am I correct, or can a gun with supersonic bullets be silenced to a significant degree? Just today, I saw a news article about poachers in Africa using "high-powered" rifles with "silencers." Is that feasible?

Most the the general news reports on firearms technology are simply bunk. Reporters and editors know little about firearms and do not seem willing to take the few minutes to google to find out that "silencers" are a misnomer. Instead, most seem to take their knowledge from Hollywood.

Instead, think of a car muffler as a mental image. This is basically the same technology applied to lessen car emission noises. A "silencer" or suppressor reduces the sound from a firearm discharge about 30 db more or less depending on efficiency and construction but does not "silence" the noise produced by the shot. Thus, instead of a 160 db discharge noise, it reduces it to 130-140 db which can reduce but not eliminate the need for hearing protection using a high powered rifle. As noted above, it does not eliminate the "crack" aka sonic boom of a bullet going supersonic and as sound waves dissipate in the atmosphere, a suppressor makes these waves less energetic and that reduces how far the noise will carry.

Search for silencer and/or suppressor threads and you will find a lot that look like this
https://www.thehighroad.org/index.php?threads/suppressors-silencers.415108/

 

[shoobe01]

To some news types (or police who feed the info to them) "high powered rifle" is a single word. There may be no other rifles.

Yes you can suppress the muzzle of supersonic rifles. Makes it nicer to shoot, much quieter generally, and much, much harder to tell where shots are coming from, which may be enough for snipers or poachers.

A few old timey suppressors had things like vented barrels; when fed normal issue supersonic ammo they would bleed off enough gas to make them subsonic on exit of the gun. But... that's not an awesome solution.

 

[Jim Watson]

Does a game animal react to the origin of a shot the way a soldier can?

John Taylor preferred plain extractors for his elephant guns. He said it was hard for them to localize the blast of the shot, but the ring of brass coming out on ejectors would draw attention. Unpleasant attention.

 

[Wichaka]

Never seen a suppressor that completely silenced a round. A suppressor cuts down the sound from the gas pressure created in the chamber and barrel another sound is from the bullet breaking the sound barrier.

300 Blackout subsonic, all one hears is the drop of the firing pin in a bolt gun...or in an AR platform, the hammer drop and the bolt cycling is all that is heard.

 

[boom boom]

Once again, most "silencers" drop the sound about 30 db--thus a .300 BO discharge using subsonic ammo will be about 115 db to 120 db. The actual sound processed by the ears depends on distance from the muzzle, material around the discharge (hard surfaces reflect sound while soft surfaces absorb it, and a few other factors etc. )

Be careful about using internet videos as examples as well as many of these are recorded using sound recorders that reduce loud sounds through noise reduction.

Note that hollywood will show revolvers with a silencer (check out the movie "The Sting" for an example when the shootout occurs between Redford's protector and an assassin trying to do his character in. "

Previous thread on the matter.
https://www.thehighroad.org/index.p...lackout-suppressed-with-subsonic-ammo.818707/

For frame of reference loudest rock bands
https://infogalactic.com/info/Loudest_band_in_the_world

and a comparison by a suppressor dealer regarding different firearms noise levels while suppressed. Note that a BB gun such as the Red Ryder still generates about 97db

https://www.dakotasilencer.com/wp-content/uploads/2014/05/Silencer_Sound_Comparsion_chart.pdf

I personally wear muffs regardless of whether a weapon is suppressed. I already have hearing loss and do not want more of it.

 

[Wichaka]

Personally witnessed it. A friend built a bolt gun in 300 BO, used subsonic rounds...220 and 250gr...'nary a sound.

I screwed one on my 300 BO pistol with 10.5" barrel, again only sound is the hammer drop and bolt cycle.

That 300 BO was developed especially for the heavier subsonic rounds. Make great house guns, won't take your hearing out.

But we're getting off track...I would think if the can is large enough, it might supress a supersonic round...but it wouldn't be user friendly.

 

[Telekinesis]

It depends on what you mean by "silenced". A supersonic round does make a sonic boom as it goes down range, but as a shooter the majority of the sound you hear is the gas as it exits the barrel. Adding a suppressor catches that gas and quiets that part of the equation.

Take a 9mm pistol:
Unsuppressed ~ 160db
Suppressed 115gr (supersonic) ~ 135dB
Suppressed 147gt (subsonic) ~ 128dB

A .300 Blk AR will give you somewhat similar numbers. A .223 AR will be around 140dB with a suppressor and standard supersonic ammo. No matter what, a supersonic round is going to meter around the 130db + range.

So you do get a substantial reduction in sound, even using supersonic ammo. Keep in mind "hearing safe" is 140 dB, and I consider "comfortable" to be the low 130dB's or below.

Suppressing a weapon shooting a supersonic round also pushes the sound to a higher frequency than either unsuppressed or suppressed/subsonic.

So, to wrap it all up: from a shooters perspective, you get a significantly lower sound level making it more comfortable to shoot (there are also accuracy, velocity, and recoil advantages if you want to get into that level of detail).
As a poacher, it lowers the overall sound signature of your shot, can make it difficult for others at a distance to locate you, and can sometimes make your shots sound like something other than a gunshot.

 

[boom boom]

As usual, YMMV but using sound meters

https://www.silencershop.com/blog/post/300-blk-impressions

Money quotes

• "Sierra 220MK bullet seated to 2.12" OAL
• 11.2 grains of A1680 powder (Seriously, this 8 lb container of powder is going to last FOREVER...)
• Remington 7.5 Primer" and

"Once again, we were using an 8" SBR for this metering - and the metering was done 1 meter from the muzzle (although we were not as exact as normal since we were just looking for ballpark numbers). The average 10-round results were:

• Unsuppressed: 163.1 dB
• Suppressed: 129.9 dB"

 

[mjsdwash]

I have heard a few newspeople call the 22lr a "high powered rifle" in the 90's and during things like the Seevakumaran James Oliver fiasco more than once. Same people who throw out "cop killer bullets" when talking about hollowpoints, or FMJ depending on politics, and what they want banned that day. I still meet people from the era that legitimately think spraying no stick pan spray on bullets makes them go through group 3 armor. The whole point is to get an idea in your head. Now in 5 years in some neighborhood get together somewhere in America, some "expert" will explain how silencers are evil because they silence "high powered rifles" so effectively you cant hear them 2 feet away, and people will believe them because they sound so confident.

 

[mjsdwash]

I forgot to add the media nationwide talked about James Oliver Seevakumaran's "arsenal" of $15 worth of 22.

 

[.308 Norma]

I have heard a few newspeople call the 22lr a "high powered rifle" in the 90's and during things like the Seevakumaran James Oliver fiasco more than once.

Watching Nightline last weekend, I actually heard a newsman refer to a shotgun as a "high powered shotgun known as a street-sweeper." He claimed it was "the same type of shotgun the police use."

 

[.308 Norma]

However, many common rounds (such as 9mm) are supersonic unless they have a heavy bullet.

I'll go a lot further than that - most (by a long ways) common rounds fire bullets at supersonic speeds. The speed of sound in air is only around 1100fps. Almost all modern day big game rifles beat that by twice, and occasionally three times.
Heck, even my 45-110 Sharps launches a 500gr bullet close to 1400fps. Of course it probably goes subsonic before it reaches the 300 yard mark - a fact ignored by Hollywierd in the movie "Quigley Down Under."

 

[cjwils]

"Was that the article where the poachers became dinner for the lions?" Yes, that is what got me going. I cannot see any rifle that can stop African big game being significantly silenced. Maybe it is about misdirection.

 

[Elkins45]

Personally witnessed it. A friend built a bolt gun in 300 BO, used subsonic rounds...220 and 250gr...'nary a sound.

I screwed one on my 300 BO pistol with 10.5" barrel, again only sound is the hammer drop and bolt cycle.

That 300 BO was developed especially for the heavier subsonic rounds. Make great house guns, won't take your hearing out.

But we're getting off track...I would think if the can is large enough, it might supress a supersonic round...but it wouldn't be user friendly.

I would love to know what brand of silencer that was.

 

[shoobe01]

Suppressors are on the NFA list because of their (at least occasional) use by poachers during the depression.

You aren't trying to hide the sound from the game, and you cannot be totally silent; just making it hard for the land owner or game warden to find you is quite enough. They are, AFAIK, somewhat common in current poaching in countries like this.

 

[Jim Watson]

Working the pits on a conventional rifle range, I kept the plugs in.
The shockwave is LOUD, even if you are a thousand yards from the muzzle blast.

 

[z7]

Suppressors do not make gunshots silent, but they make a huge difference for the shooter and those nearby

You still want earpro with most high power rifles, but the shot is much less offensive for everyone around

 

[dbmjr1]

I saw the same article about poaching Rhinos. The poachers were eaten by lions.

Yes, a suppressor is effective, even with a super sonic projectile.

The suppressor will still effectively reduce the report of the rifle, making it more difficult to determine where the shot came from.

 

[jmorris]

With a suppressor you can make most any gun make less noise. I have never heard any that were truly silent.

Best I have done so far is a bolt action .22 with subs and a suppressor, makes slightly less noise than a dry fire.



I’ll do better if I can ever get my hands on one of the Beeman/Krico rifles from the mid 80’s though...

 

[Carl N. Brown]

The car muffler analog works. In fact, "silencer" is what Brits call auto mobile mufflers. To be pendantic about it, firearms "silencers" and auto mobile "mufflers" are just sound suppressors that reduce sound from a gun or motor down to a level less annoying or (hopefully) less damaging to the ears of the shooter.

The supersonic bullet will still make a crack, but that's going down range.

(The sensors that detect gunshots and direction of fire will also detect the pressure change caused by the firing of a gun with an NFA silencer.)

 

[JeffG]

To be clear, suppressors/silencers are not evil. It is the act of poaching or other crimes that is the problem. Painting silencers as nefarious devices is a platform for anti gunners and anti hunters.

 

[Wichaka]

I would love to know what brand of silencer that was.

Yankee Hill muzzle device and a Dead Air suppressor.

To get dead quiet, you need to run it in a bolt gun.

Check the net, there's plenty of videos showing almost dead quiet coming from the use of an AR platform.

 

[JeffG]

For centerfire rifle, this is about as quiet as it gets. 308 Hog Hunter, shooting 180gr Sierra roundnose at about 950 fps. It was windy, and winter, so the sound of the shot carried a bit. When listening to the shot, compare the shot noise, to the sound of the brass hitting the table top. Gemtech Dagger, direct thread suppressor.

There is an impact shot on a water jug at 50 yards. Not the massive destruction you would see with full throttle loads. When shooting paper, I use 1/2 inch shoot 'n see repair pasters as targets. Very accurate. As you can see, not exactly "cat sneeze" quiet. Not a gallery load to shoot in your back yard.